Dramatic resurgence of malaria after 7 years of intensive vector control interventions in Eastern Uganda.

Background: Tororo District, Uganda experienced a dramatic decrease in malaria burden from 2015-19 following 5 years of indoor residual spraying (IRS) with carbamate (Bendiocarb) and then organophosphate (Actellic) insecticides. However, a marked resurgence occurred in 2020, which coincided with a change to a clothianidin-based IRS formulations (Fludora Fusion/SumiShield). To quantify the magnitude of the resurgence, investigate causes, and evaluate the impact of a shift back to IRS with Actellic in 2023, we assessed changes in malaria metrics in regions within and near Tororo District. Methods: Malaria surveillance data from Nagongera Health Center, Tororo District was included from 2011-2023. In addition, a cohort of 667 residents from 84 houses was followed from August 2020 through September 2023 from an area bordering Tororo and neighboring Busia District, where IRS has never been implemented. Cohort participants underwent passive surveillance for clinical malaria and active surveillance for parasitemia every 28 days. Mosquitoes were collected in cohort households every 2 weeks using CDC light traps. Female Anopheles were speciated and tested for sporozoites and phenotypic insecticide resistance. Temporal comparisons of malaria metrics were stratified by geographic regions. Findings: At Nagongera Health Center average monthly malaria cases varied from 419 prior to implementation of IRS; to 56 after 5 years of IRS with Bendiocarb and Actellic; to 1591 after the change in IRS to Fludora Fusion/SumiShield; to 155 after a change back to Actellic. Among cohort participants living away from the border in Tororo, malaria incidence increased over 8-fold (0.36 vs. 2.97 episodes per person year, p<0.0001) and parasite prevalence increased over 4-fold (17% vs. 70%, p<0.0001) from 2021 to 2022 when Fludora Fusion/SumiShield was used. Incidence decreased almost 5-fold (2.97 vs. 0.70, p<0.0001) and prevalence decreased by 39% (70% vs. 43%, p<0.0001) after shifting back to Actellic. There was a similar pattern among those living near the border in Tororo, with increased incidence between 2021 and 2022 (0.93 vs. 2.40, p<0.0001) followed by a decrease after the change to Actellic (2.40 vs. 1.33, p<0.001). Among residents of Busia, malaria incidence did not change significantly over the 3 years of observation. Malaria resurgence in Tororo was temporally correlated with the replacement of An. gambiae s.s. by An. funestus as the primary vector, with a marked decrease in the density of An. funestus following the shift back to IRS with Actellic. In Busia, An. gambiae s.s. remained the primary vector throughout the observation period. Sporozoite rates were approximately 50% higher among An. funestus compared to the other common malaria vectors. Insecticide resistance phenotyping of An. funestus revealed high tolerance to clothianidin, but full susceptibility to Actellic. Conclusions: A dramatic resurgence of malaria in Tororo was temporally associated with a change to clothianidin-based IRS formulations and emergence of An. funestus as the predominant vector. Malaria decreased after a shift back to IRS with Actellic. This study highlights the ability of malaria vectors to rapidly circumvent control efforts and the importance of high-quality surveillance systems to assess the impact of malaria control interventions and generate timely, actionable data.

Plasmodium falciparum genetic diversity and multiplicity of infection based on msp-1, msp-2, glurp and microsatellite genetic markers in sub-Saharan Africa: a systematic review and meta-analysis.

BACKGROUND: In sub-Saharan Africa (SSA), Plasmodium falciparum causes most of the malaria cases. Despite its crucial roles in disease severity and drug resistance, comprehensive data on Plasmodium falciparum genetic diversity and multiplicity of infection (MOI) are sparse in SSA. This study summarizes available information on genetic diversity and MOI, focusing on key markers (msp-1, msp-2, glurp, and microsatellites). The systematic review aimed to evaluate their influence on malaria transmission dynamics and offer insights for enhancing malaria control measures in SSA. METHODS: The review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Two reviewers conducted article screening, assessed the risk of bias (RoB), and performed data abstraction. Meta-analysis was performed using the random-effects model in STATA version 17. RESULTS: The review included 52 articles: 39 cross-sectional studies and 13 Randomized Controlled Trial (RCT)/cohort studies, involving 11,640 genotyped parasite isolates from 23 SSA countries. The overall pooled mean expected heterozygosity was 0.65 (95% CI: 0.51-0.78). Regionally, values varied: East (0.58), Central (0.84), Southern (0.74), and West Africa (0.69). Overall pooled allele frequencies of msp-1 alleles K1, MAD20, and RO33 were 61%, 44%, and 40%, respectively, while msp-2 I/C 3D7 and FC27 alleles were 61% and 55%. Central Africa reported higher frequencies (K1: 74%, MAD20: 51%, RO33: 48%) than East Africa (K1: 46%, MAD20: 42%, RO33: 31%). For msp-2, East Africa had 60% and 55% for I/C 3D7 and FC27 alleles, while West Africa had 62% and 50%, respectively. The pooled allele frequency for glurp was 66%. The overall pooled mean MOI was 2.09 (95% CI: 1.88-2.30), with regional variations: East (2.05), Central (2.37), Southern (2.16), and West Africa (1.96). The overall prevalence of polyclonal Plasmodium falciparum infections was 63% (95% CI: 56-70), with regional prevalences as follows: East (62%), West (61%), Central (65%), and South Africa (71%). CONCLUSION: The study shows substantial regional variation in Plasmodium falciparum parasite genetic diversity and MOI in SSA. These findings suggest a need for malaria control strategies and surveillance efforts considering regional-specific factors underlying Plasmodium falciparum infection.

Perinatal care and its association with perinatal death among women attending care in three district hospitals of western Uganda.

BACKGROUND: Provision of effective care to all women and newborns during the perinatal period is a viable strategy for achieving the Sustainable Development Goal 3 targets on reducing maternal and neonatal mortality. This study examined perinatal care (antenatal, intrapartum, postpartum) and its association with perinatal deaths at three district hospitals in Bunyoro region, Uganda. METHODS: A cross-sectional study was conducted in which a questionnaire was administered consecutively to 872 postpartum women before discharge who had attended antenatal care and given birth in the study hospitals. Data on care received during antenatal, labour, delivery, and postpartum period, and perinatal outcome were extracted from medical records of the enrolled postnatal women using a pre-tested structured tool. The care received from antenatal to 24 h postpartum period was assessed against the standard protocol of care established by World Health Organization (WHO). Poisson regression was used to assess the association between care received and perinatal death. RESULTS: The mean age of the women was 25 years (standard deviation [SD] 5.95). Few women had their blood tested for hemoglobin levels, HIV, and Syphilis (n = 53, 6.1%); had their urine tested for glucose and proteins (n = 27, 3.1%); undertook an ultrasound scan (n = 262, 30%); and had their maternal status assessed (n = 122, 14%) during antenatal care as well as had their uterus assessed for contraction and bleeding during postpartum care (n = 63, 7.2%). There were 19 perinatal deaths, giving a perinatal mortality rate of 22/1,000 births (95% Confidence interval [CI] 8.1-35.5). Of these 9 (47.4%) were stillbirths while the remaining 10 (52.6%) were early neonatal deaths. In the antenatal phase, only fetal examination was significantly associated with perinatal death (adjusted prevalence ratio [aPR] = 0.22, 95% CI 0.1-0.6). No significant association was found between perinatal deaths and care during labour, delivery, and the early postpartum period. CONCLUSION: Women did not receive all the required perinatal care during the perinatal period. Perinatal mortality rate in Bunyoro region remains high, although it's lower than the national average. The study shows a reduction in the proportion of perinatal deaths for pregnancies where the mother received fetal monitoring. Strategies focused on strengthened fetal status monitoring such as fetal movement counting methods and fetal heart rate monitoring devices during pregnancy need to be devised to reduce the incidence of perinatal deaths. Findings from the study provide valuable information that would support the strengthening of perinatal care services for improved perinatal outcomes.

Dyslipidemia among adult people living with HIV on dolutegravir - based antiretroviral therapy at a private tertiary hospital in Kampala, Uganda: burden and determinants.

BACKGROUND: Understanding the burden of dyslipidemia and its associated factors among adult people living with HIV on dolutegravir (DTG) based anti-retroviral therapy (ART) is critical to provide clinical guidance and risk reduction strategies in our setting. METHODS: We conducted a cross-sectional study on adult people living with HIV on DTG based ART between July and August 2022 at Mengo Hospital, a private not for profit missionary hospital owned by the Church of Uganda. Dyslipidemia was defined as: Total cholesterol (TC) ≥ 5.2 mmol/l, or high-density lipoprotein (HDL) < 1 mmol/l for men and < 1.3 mmol/l for women, or triglycerides (TG) ≥ 1.7 mmol/l, and low-density lipoprotein (LDL) ≥ 3.4 mmol/l. A participant was considered to have dyslipidemia if they had any of the lipid profile parameters in the above ranges. Socio-demographic information, clinical data and behavioral characteristics were collected. Fasting lipid profile and fasting blood glucose levels were also measured. Bivariate and multivariate analyses were done using a generalized linear model regression of the Poisson family with a log link (modified Poisson) using robust standard errors since the prevalence of dyslipidemia was more than 10%. Adjusted prevalence ratios (PR) were reported with their 95% confidence intervals (CI). A p-value of less than 0.05 was considered statistically significant. RESULTS: A total of 341 participants were included. The prevalence of dyslipidemia was 78.0%, (95%CI:73.3-82.1). The highest prevalence was for low HDL (72.1%, 95%CI 67.1-76.7) followed by high TG (20.2%, 95%CI: 16.3-24.9), high TC (12.0%, 95%CI: 9.0-15.9) and high LDL (6.5%, 95%CI: 4.3-9.6). Female sex (aPR:1.55, 95%CI: 1.32-1.84, p < 0.001) and previous use of protease inhibitor (PI) based ART regimen (aPR:1.26, 95%CI: 1.04-1.53, p = 0.018) were significantly associated with dyslipidemia. CONCLUSION: We demonstrate that the prevalence of dyslipidemia is very high as it was present in more than three quarters of the study participants. Female sex and previous use of PI based ART regimen were significantly associated with dyslipidemia. Management of dyslipidemia should be integrated in the HIV treatment package and we recommend further inquiry into the temporal relationship between dyslipidemia and DTG among ART patients, if any.

Perspectives of people living with HIV on barriers to timely ART initiation following referral for antiretroviral therapy: A qualitative study at an urban HIV clinic in Kampala, Uganda.

Early initiation of antiretroviral therapy (ART) after HIV diagnosis prevents HIV transmission, progression of HIV to AIDS and improves quality of life. However, little is known about the barriers to timely ART initiation among patients who test HIV positive in settings different from where they will receive HIV treatment, hence are referred in the routine setting. Therefore, we explored the perspectives of people living with HIV on barriers faced to initiate ART following HIV testing and referral for treatment. In this qualitative study, we purposively sampled and enrolled 17 patients attending the Mulago ISS clinic. We selected patients (≥18 years) who previously were received as referrals for HIV treatment and had delayed ART initiation, as ascertained from their records. We conducted in-depth interviews, which were audio recorded, transcribed and translated. We used Atlas.ti version 9 software for data management. Data analysis followed thematic and framework analysis techniques and we adopted the socio-ecological model to categorize final themes. Key themes were found at organizational level including; negative experiences at the place of HIV diagnosis attributed to inadequate counselling and support, unclear communication of HIV-positive results and ambiguous referral procedures; and, long waiting time when patients reached the HIV clinic. At individual level, the themes identified were; immediate denial with late acceptance of HIV-positive results attributed to severe emotional and psychological distress at receiving results, fear of perceived side effects and long duration on ART. At interpersonal level, we found that anticipated and enacted stigma after HIV diagnosis resulted in non-disclosure, discrimination and lack of social support. We found that challenges at entry (during HIV test) and navigation of the HIV care system in addition to individual and interpersonal factors contributed to delayed ART initiation. Interventions during HIV testing would facilitate early ART initiation among patients referred for HIV care.

Impact of high human genetic diversity in Africa on immunogenicity and efficacy of RTS,S/AS01 vaccine.

In modern medicine, vaccination is one of the most effective public health strategies to prevent infectious diseases. Indisputably, vaccines have saved millions of lives by reducing the burden of many serious infections such as polio, tuberculosis, measles, pneumonia, and tetanus. Despite the recent recommendation by the World Health Organization (WHO) to roll out RTS,S/AS01, this malaria vaccine still faces major challenges of variability in its efficacy partly due to high genetic variation in humans and malaria parasites. Immune responses to malaria vary between individuals and populations. Human genetic variation in immune system genes is the probable cause for this heterogeneity. In this review, we will focus on human genetic factors that determine variable responses to vaccination and how variation in immune system genes affect the immunogenicity and efficacy of the RTS,S/AS01 vaccine.

Seroprevalence of Antibodies to SARS-CoV-2 in Rural Households in Eastern Uganda, 2020-2022.

Importance: Estimating the true burden of SARS-CoV-2 infection has been difficult in sub-Saharan Africa owing to asymptomatic infections and inadequate testing capacity. Antibody responses from serologic surveys can provide an estimate of SARS-CoV-2 exposure at the population level. Objective: To estimate SARS-CoV-2 seroprevalence, attack rates, and reinfection in eastern Uganda using serologic surveillance from 2020 to early 2022. Design, Setting, and Participants: This cohort study was conducted in the Tororo and Busia districts of eastern Uganda. Plasma samples from participants in the Program for Resistance, Immunology, Surveillance, and Modeling of Malaria in Uganda Border Cohort were obtained at 4 sampling intervals: October to November 2020, March to April 2021, August to September 2021, and February to March 2022. Each participant contributed up to 4 time points for SARS-CoV-2 serology, with almost half of all participants contributing at all 4 time points, and almost 90% contributing at 3 or 4 time points. Information on SARS-CoV-2 vaccination status was collected from participants, with the earliest reported vaccinations in the cohort occurring in May 2021. Main Outcomes and Measures: The main outcomes of this study were antibody responses to the SARS-CoV-2 spike protein as measured with a bead-based serologic assay. Individual-level outcomes were aggregated to population-level SARS-CoV-2 seroprevalence, attack rates, and boosting rates. Estimates were weighted by the local age distribution according to census data. Results: A total of 1483 samples from 441 participants living in 76 households were tested. Of the 441 participants, 245 (55.6%) were female, and their mean (SD) age was 16.04 (16.04) years. By the end of the Delta wave and before widespread vaccination, adjusted SARS-CoV-2 seroprevalence was 67.7% (95% credible interval [CrI], 62.5%-72.6%) in the study population. During the subsequent Omicron wave, 84.8% (95% CrI, 67.9%-93.7%) of unvaccinated, previously seronegative individuals were infected for the first time, and 50.8% (95% CrI, 40.6%-59.7%) of unvaccinated, already seropositive individuals were likely reinfected, leading to an overall seropositivity of 96.0% (95% CrI, 93.4%-97.9%) in this population. These results suggest a lower probability of reinfection in individuals with higher preexisting antibody levels. There was evidence of household clustering of SARS-CoV-2 seroconversion. No significant associations were found between SARS-CoV-2 seroconversion and gender, household size, or recent Plasmodium falciparum malaria exposure. Conclusions and Relevance: In this cohort study in a rural population in eastern Uganda, there was evidence of very high SARS-CoV-2 infection rates throughout the pandemic inconsistent with national level case data and high reinfection rates during the Omicron wave.

Predictors of delayed Anti-Retroviral Therapy initiation among adults referred for HIV treatment in Uganda: a cross-sectional study.

BACKGROUND: Uganda's current guidelines recommend immediate initiation of Anti-Retroviral Therapy (ART) for persons living with HIV in order to reduce HIV/AIDS related morbidity and mortality. However, not all eligible PLHIV initiate ART within the recommended time following HIV diagnosis. We assessed the prevalence and factors associated with delayed ART initiation among PLHIV referred for ART initiation, five years since rolling out the test and treat guidelines. METHODS: In this cross-sectional study, we enrolled adult patients referred to Mulago Immune Suppressive Syndrome (Mulago ISS) clinic for ART initiation from January 2017 to May 2021. We collected data on socio-demographics, HIV diagnosis and referral circumstances, and time to ART initiation using a questionnaire. The outcome of interest was proportion of patients that delayed ART, defined as spending more than 30 days from HIV diagnosis to ART initiation. We performed multivariable logistic regression and identified significant factors. RESULTS: A total of 312 patients were enrolled of which 62.2% were female. The median (inter-quartile range [IQR]) age and baseline CD4 count of the patients were 35 (28-42) years and 315 (118.8-580.5) cells/µL respectively. Forty-eight (15.4%) patients delayed ART initiation and had a median (IQR) time to ART of 92 (49.0-273.5) days. The factors associated with delayed ART initiation were; 1) having had the HIV diagnosis made from a private health facility versus public, (adjusted odds ratio [aOR] = 2.4 (95% confidence interval [CI] 1.1-5.5); 2) initial denial of positive HIV test results, aOR = 5.4 (95% CI: 2.0-15.0); and, 3) having not received a follow up phone call from the place of HIV diagnosis, aOR = 2.8 (95% CI: 1.2-6.8). CONCLUSION: There was significant delay of ART initiation among referred PLHIV within 5 years after the rollout of test and treat guidelines in Uganda. Health system challenges in the continuity of HIV care services negatively affects timely ART initiation among referred PLHIV in Uganda.

Measures of malaria transmission, infection, and disease in an area bordering two districts with and without sustained indoor residual spraying of insecticide in Uganda.

Tororo District, in Eastern Uganda, experienced a dramatic decline in malaria burden starting in 2014 following the implementation of indoor residual spraying of insecticide (IRS) in the setting of repeated long-lasting insecticide treated nets (LLINs) distribution campaigns. However, in 2020 malaria began to resurge in Tororo following a change in the active ingredient used for IRS. In this study, epidemiological measures of malaria were compared shortly after the resurgence between two parishes in Tororo District (Kayoro and Osukuru) and one contiguous parish in Busia District (Buteba), where IRS has never been implemented. A cohort of 483 residents from 80 randomly selected households were followed from August 2020 to January 2021. Mosquitoes were collected every 2 weeks using CDC light traps in rooms where participants slept; parasitemia and gametoctyemia measured every 4 weeks by microscopy and PCR; and symptomatic malaria measured by passive surveillance. The annual entomological inoculation rate was significantly higher in Buteba (108.2 infective bites/person/year), compared to Osukuru (59.0, p = 0.001) and Kayoro (27.4, p<0.001). Overall, parasite prevalence was 19.5% by microscopy and 50.7% by PCR, with no significant differences between the three parishes. Among infected individuals, gametocyte prevalence by PCR was 45.5% and similar between sites. The incidence of malaria was significantly higher in Osukuru (2.46 episodes PPY) compared to Buteba (1.47, p = 0.005) and Kayoro (1.09, p<0.001). For participants over 15 years of age, the risk of symptomatic malaria if microscopic parasitemia was present was higher in Osukuru (relative risk [RR] = 2.99, p = 0.03) compared to Buteba. These findings highlight the complex relationships between measures of malaria transmission, infection, and disease, and the potential for excess disease burden, possibly due to waning immunity, in areas where vector control interventions begin to fail after a sustained period of highly effective control.

Malaria diagnostic and treatment practices for febrile children under 5 years at two general hospitals in Karamoja, a high transmission setting in Uganda.

BACKGROUND: Malaria is one of the leading causes of morbidity and mortality among children under 5 years of age in Uganda. Although Karamoja sub-region has the highest prevalence of malaria, and one of the highest case fatality rates in children under 5 years, information on malaria case management for the sub-region is scarce. The study evaluated the malaria diagnostic and treatment practices, as well as the factors associated with inappropriate care for children under 5 years of age presenting with fever in two public hospitals within the sub-region. METHODS: A cross-sectional study was conducted amongst 857 children under 5 years of age who presented with fever at Abim and Kaabong general hospitals between February and March 2020. A questionnaire was administered to the primary caregiver during exit/bedside interviews to collect socio-demographic information. The participant clinical notes were reviewed to capture information on laboratory tests conducted, diagnosis given, and treatment prescribed. In addition, a health facility assessment was conducted and information on healthcare workers was collected. The healthcare worker and facility data was linked to the participant's hospital visit. Main outcome measures were malaria diagnostic and treatment practices. RESULTS: Of the 857 children enrolled, 820 (95.7%) had a malaria diagnostic test done and 623 (76.0%) tested positive for malaria. All test positive children received anti-malarial treatment, however, only 424/623 (68.1%) received the recommended anti-malarial drug and 376/424 (88.7%) received the right dose of the treatment. Inappropriate diagnosis/treatment was in 321 (37.5%) of the enrolled participants. Factors associated with inappropriate diagnosis/treatment included: lack of recommended anti-malarials on the day of the visit (Prevalence Ratio [PR] = 2.1, 95% confidence interval [CI] 1.8-2.4), hospital where care was sought (PR = 0.4, 95% CI 0.3-0.5), being managed by a recently supervised health worker (PR = 0.5, 95% CI 0.2-0.9), and health worker cadre (PR = 0.8, 95% CI 0.7-0.9). CONCLUSION: The prevalence of inappropriate malaria diagnosis and treatment in the Karamoja sub-region was high with approximately one in every three children receiving inappropriate care. This was majorly influenced by health system factors, which if improved upon may reduce malaria-related mortalities in the sub-region a vital step in meeting the country's target of zero deaths from malaria by 2030.

East Africa International Center of Excellence for Malaria Research: Impact on Malaria Policy in Uganda.

Malaria is the leading cause of disease burden in sub-Saharan Africa. In 2010, the East Africa International Center of Excellence for Malaria Research, also known as the Program for Resistance, Immunology, Surveillance, and Modeling of Malaria (PRISM), was established to provide a comprehensive approach to malaria surveillance in Uganda. We instituted cohort studies and a robust malaria and entomological surveillance network at selected public health facilities that have provided a platform for monitoring trends in malaria morbidity and mortality, tracking the impact of malaria control interventions (indoor residual spraying of insecticide [IRS], use of long-lasting insecticidal nets [LLINs], and case management with artemisinin-based combination therapies [ACTs]), as well as monitoring of antimalarial drug and insecticide resistance. PRISM studies have informed Uganda's malaria treatment policies, guided selection of LLINs for national distribution campaigns, and revealed widespread pyrethroid resistance, which led to changes in insecticides delivered through IRS. Our continuous engagement and interaction with policy makers at the Ugandan Ministry of Health have enabled PRISM to share evidence, best practices, and lessons learned with key malaria stakeholders, participate in malaria control program reviews, and contribute to malaria policy and national guidelines. Here, we present an overview of interactions between PRISM team members and Ugandan policy makers to demonstrate how PRISM's research has influenced malaria policy and control in Uganda.

East Africa International Center of Excellence for Malaria Research: Summary of Key Research Findings.

The Program for Resistance, Immunology, Surveillance, and Modeling of Malaria (PRISM) has been conducting malaria research in Uganda since 2010 to improve the understanding of the disease and measure the impact of population-level control interventions in the country. Here, we will summarize key research findings from a series of studies addressing routine health facility-based surveillance, comprehensive cohort studies, studies of the molecular epidemiology, and transmission of malaria, evaluation of antimalarial drug efficacy, and resistance across the country, and assessments of insecticide resistance. Among our key findings are the following. First, we found that in historically high transmission areas of Uganda, a combination of universal distribution of long-lasting insecticidal-treated nets (LLINs) and sustained indoor residual spraying (IRS) of insecticides lowered the malaria burden greatly, but marked resurgences occurred if IRS was discontinued. Second, submicroscopic infections are common and key drivers of malaria transmission, especially in school-age children (5-15 years). Third, markers of drug resistance have changed over time, with new concerning emergence of markers predicting resistance to artemisinin antimalarials. Fourth, insecticide resistance monitoring has demonstrated high levels of resistance to pyrethroids, appreciable impact of the synergist piperonyl butoxide to pyrethroid susceptibility, emerging resistance to carbamates, and complete susceptibility of malaria vectors to organophosphates, which could have important implications for vector control interventions. Overall, PRISM has yielded a wealth of information informing researchers and policy-makers on the malaria burden and opportunities for improved malaria control and eventual elimination in Uganda. Continued studies concerning all the types of surveillance discussed above are ongoing.

Simulating the Impacts of Augmenting Intensive Vector Control with Mass Drug Administration or Test-and-Treat Strategies on the Malaria Infectious Reservoir.

Highly effective vector control can reduce malaria burden significantly, but individuals with parasitemia provide a potential reservoir for onward transmission. We performed an empirical, non-parametric simulation based on cohort data from Tororo District, Uganda-an area with historically high but recently reduced malaria transmission-to estimate the effects of mass drug administration (MDA) and test-and-treat on parasite prevalence. We estimate that a single round of MDA would have accelerated declines in parasite prevalence dramatically over 2 years (cumulative parasite prevalence ratio [PPR], 0.34). This decline was mostly during the first year of administration (PPR, 0.23) and waned by 23 months (PPR, 0.74). Test-and-treat using a highly sensitive diagnostic had nearly the same effect as MDA at 1 year (PPR, 0.27) and required many fewer treatments. The impact of test-and-treat using a standard diagnostic was modest (PPR, 0.58 at 1 year). Our analysis suggests that in areas experiencing a dramatic reduction in malaria prevalence, MDA or test-and-treat with a highly sensitive diagnostic may be an effective way of reducing or eliminating the infectious reservoir temporarily. However, for sustained benefits, repeated rounds of the intervention or additional interventions are required.

LLIN Evaluation in Uganda Project (LLINEUP2)-Factors associated with coverage and use of long­lasting insecticidal nets following the 2020-21 national mass distribution campaign: a cross-sectional survey of 12 districts.

BACKGROUND: In 2020-2021, long-lasting insecticidal nets (LLINs) were distributed nationwide in Uganda during the COVID-19 pandemic. A cross-sectional survey was conducted in 12 districts to evaluate the impact of the campaign 1-5 months after LLIN distribution. METHODS: During April-May 2021, households were randomly selected from target areas (1-7 villages) surrounding 12 government-run health facilities established as Malaria Reference Centres; at least 50 households were enrolled per cluster. Outcomes included household ownership of LLINs distributed through the universal coverage campaign (UCC) (at least one UCC LLIN), adequate coverage of UCC LLINs (at least one UCC LLIN per 2 residents), and use of LLINs (resident slept under a LLIN the previous night). Multivariate logistic regression models were used to identify household- and individual-level factors associated with outcomes, controlling for clustering around health facilities. RESULTS: In total, 634 households, with 3342 residents and 1631 bed-nets, were included. Most households (93.4%) owned at least 1 UCC LLIN, but only 56.8% were adequately covered by UCC LLINs. In an adjusted analysis, the factor most strongly associated with adequate coverage by UCC LLINs was fewer household residents (1-4 vs 7-14; adjusted odds ratio [aOR] 12.96, 95% CI 4.76-35.26, p < 0.001; 5-6 vs 7-14 residents; aOR 2.99, 95% CI 1.21-7.42, p = 0.018). Of the 3166 residents of households that owned at least one UCC LLIN, only 1684 (53.2%) lived in adequately covered households; 89.9% of these used an LLIN the previous night, compared to 1034 (69.8%) of 1482 residents living in inadequately covered households. In an adjusted analysis, restricted to residents of inadequately covered households, LLIN use was higher in children under-five than those aged 5-15 years (aOR 3.04, 95% CI 2.08-4.46, p < 0.001), and higher in household heads than distantly-related residents (aOR 3.94, 95% CI 2.38-6.51, p < 0.001). CONCLUSIONS: Uganda's 2021-21 campaign was successful, despite the COVID-19 pandemic. In future campaigns, strategies should be adopted to ensure high LLIN coverage, particularly for larger households. A better understanding of the drivers of LLIN use within households is needed to guide future interventions, educational messages, and behaviour change communication strategies; school-aged children and distantly-related residents appear vulnerable and could be targeted.

Prevalence and factors associated with anaemia in children aged 6-24 months living a high malaria transmission setting in Burundi.

BACKGROUND: In very young children, anaemia has been linked to increased morbidity, mortality and poor cognitive development. Although Burundi has a high burden of anaemia, which may be worsened by the high burden of malaria, little is known about the extent of the problem in very young children who are most at risk of severe disease. We estimated the prevalence, and assessed the factors associated with anaemia in children aged 6-24 months using baseline data collected as part of an on-going study evaluating the effect of Micronutrient supplementation on anaemia and cognition among children in high malaria transmission settings in Burundi. METHODS: Between February and March 2020, surveys were conducted in 498 households within the catchment area of Mukenke Health Center. One child aged 6-24 months was selected per household to participate in the survey. Following written informed consent, we administered a questionnaire to the child's primary caregiver to capture information on child's demographics, nutritional status, food intake, health (status, and morbidity and treatment-seeking practices), as well as the household markers of wealth. A physical exam was conducted, and a blood sample was collected to: 1) assess for presence of plasmodium infection using a rapid diagnosis test; 2) estimate the haemoglobin levels using a portable haemocue machine. A stool sample was also collected to examine for the presence of helminth infections. RESULTS: The prevalence of anaemia was 74.3% (95% confidence interval [CI] 61.5%-84.0%), with most of the anaemic study participants classified as having moderate anaemia (59.2%). A total of 62 (12.5%) participants had positive malaria rapid diagnosis tests. Factors significantly associated with higher odds of developing anaemia included not receiving deworming medication (adjusted Odd ratio [aOR] = 3.54, 95% CI 1.79-6.99, p<0.001), the child's home location (Mukenke II: aOR = 2.22, 95% CI 1.89-2.62, p<0.001; Mukenke: aOR = 2.76, 95% CI 2.46-3.10, p<0.001 and Budahunga: aOR = 3.12, 95% CI 2. 94-3.31, p<0.001) and the child's age group (Children aged 6-11 months: aOR = 2.27, 95% CI 1.32-3.91, p<0.001). Education level was inversely associated with less odds of anaemia: child's primary care giver with a secondary (aOR = 0.67; 95% CI: 0.47-0.95, p = 0,024) and tertiary education level (aOR = 0.48; 95% CI: 0.38-0.61, p<0.001). CONCLUSION: Anaemia is highly prevalent among young children in high malaria transmission setting. Anaemia is more prevalent among children who not dewormed and those with malaria. To prevent the long-term adverse outcomes of the anaemia in children, policy makers should focus on improving uptake of the deworming and malaria prevention programs, promote preventive interventions and improve the education of women especially in families with very young children.

Reconstructing the SARS-CoV-2 epidemic in eastern Uganda through longitudinal serosurveillance in a malaria cohort.

Importance: Estimating the true burden of SARS-CoV-2 infection has been difficult in sub-Saharan Africa due to asymptomatic infections and inadequate testing capacity. Antibody responses from serologic surveys can provide an estimate of SARS-CoV-2 exposure at the population level. Objective: To estimate SARS-CoV-2 seroprevalence, attack rates, and re-infection in eastern Uganda using serologic surveillance from 2020 to early 2022. Design: Plasma samples from participants in the Program for Resistance, Immunology, Surveillance, and Modeling of Malaria in Uganda (PRISM) Border Cohort were obtained at four sampling intervals: October-November 2020; March-April 2021; August-September 2021; and February-March 2022. Setting: Tororo and Busia districts, Uganda. Participants: 1,483 samples from 441 participants living in 76 households were tested. Each participant contributed up to 4 time points for SARS-CoV-2 serology, with almost half of all participants contributing at all 4 time points, and almost 90% contributing at 3 or 4 time points. Information on SARS-CoV-2 vaccination status was collected from participants, with the earliest reported vaccinations in the cohort occurring in May 2021. Main Outcomes and Measures: The main outcomes of this study were antibody responses to the SARS-CoV-2 spike protein as measured with a bead-based serologic assay. Individual-level outcomes were aggregated to population-level SARS-CoV-2 seroprevalence, attack rates, and boosting rates. Estimates were weighted by the local age distribution based on census data. Results: By the end of the Delta wave and before widespread vaccination, nearly 70% of the study population had experienced SARS-CoV-2 infection. During the subsequent Omicron wave, 85% of unvaccinated, previously seronegative individuals were infected for the first time, and ~50% or more of unvaccinated, already seropositive individuals were likely re-infected, leading to an overall 96% seropositivity in this population. Our results suggest a lower probability of re-infection in individuals with higher pre-existing antibody levels. We found evidence of household clustering of SARS-CoV-2 seroconversion. We found no significant associations between SARS-CoV-2 seroconversion and gender, household size, or recent Plasmodium falciparum malaria exposure. Conclusions and Relevance: Findings from this study are consistent with very high infection rates and re-infection rates for SARS-CoV-2 in a rural population from eastern Uganda throughout the pandemic.

The influence of the environment and indoor residual spraying on malaria risk in a cohort of children in Uganda.

Studies have estimated the impact of the environment on malaria incidence although few have explored the differential impact due to malaria control interventions. Therefore, the objective of the study was to evaluate the effect of indoor residual spraying (IRS) on the relationship between malaria and environment (i.e. rainfall, temperatures, humidity, and vegetation) using data from a dynamic cohort of children from three sub-counties in Uganda. Environmental variables were extracted from remote sensing sources and averaged over different time periods. General linear mixed models were constructed for each sub-counties based on a log-binomial distribution. The influence of IRS was analysed by comparing marginal effects of environment in models adjusted and unadjusted for IRS. Great regional variability in the shape (linear and non-linear), direction, and magnitude of environmental associations with malaria risk were observed between sub-counties. IRS was significantly associated with malaria risk reduction (risk ratios vary from RR = 0.03, CI 95% [0.03-0.08] to RR = 0.35, CI95% [0.28-0.42]). Model adjustment for this intervention changed the magnitude and/or direction of environment-malaria associations, suggesting an interaction effect. This study evaluated the potential influence of IRS in the malaria-environment association and highlighted the necessity to control for interventions when they are performed to properly estimate the environmental influence on malaria. Local models are more informative to guide intervention program compared to national models.

Perinatal care in Western Uganda: Prevalence and factors associated with appropriate care among women attending three district hospitals.

BACKGROUND: Perinatal mortality remains high globally and remains an important indicator of the quality of a health care system. To reduce this mortality, it is important to provide the recommended care during the perinatal period. We assessed the prevalence and factors associated with appropriate perinatal care (antenatal, intrapartum, and postpartum) in Bunyoro region, Uganda. Results from this study provide valuable information on the perinatal care services and highlight areas of improvement for better perinatal outcomes. METHODS: A cross sectional survey was conducted among postpartum mothers attending care at three district hospitals in Bunyoro. Following consent, a questionnaire was administered to capture the participants' demographics and data on care received was extracted from their antenatal, labour, delivery, and postpartum records using a pre-tested structured tool. The care received by women was assessed against the standard protocol established by World Health Organization (WHO). Poisson regression with robust standard errors was used to assess factors associated with appropriate postpartum care. RESULTS: A total of 872 mothers receiving care at the participating hospitals between March and June 2020 were enrolled in the study. The mean age of the mothers was 25 years (SD = 5.95). None of the mothers received appropriate antenatal or intrapartum care, and only 3.8% of the participants received appropriate postpartum care. Factors significantly associated with appropriate postpartum care included mothers being >35 years of age (adjusted prevalence ratio [aPR] = 11.9, 95% confidence interval [CI] 2.8-51.4) and parity, with low parity (2-3) and multiparous (>3) mothers less likely to receive appropriate care than prime gravidas (aPR = 0.3, 95% CI 0.1-0.9 and aPR = 0.3, 95% CI 0.1-0.8 respectively). CONCLUSIONS: Antenatal, intrapartum, and postpartum care received by mothers in this region remains below the standard recommended by WHO, and innovative strategies across the continuum of perinatal care need to be devised to prevent mortality among the mothers. The quality of care also needs to be balanced for all mothers irrespective of the age and parity.

Gender difference in the incidence of malaria diagnosed at public health facilities in Uganda.

BACKGROUND: Routine malaria surveillance data in Africa primarily come from public health facilities reporting to national health management information systems. Although information on gender is routinely collected from patients presenting to these health facilities, stratification of malaria surveillance data by gender is rarely done. This study evaluated gender difference among patients diagnosed with parasitological confirmed malaria at public health facilities in Uganda. METHODS: This study utilized individual level patient data collected from January 2020 through April 2021 at 12 public health facilities in Uganda and cross-sectional surveys conducted in target areas around these facilities in April 2021. Associations between gender and the incidence of malaria and non-malarial visits captured at the health facilities from patients residing within the target areas were estimated using poisson regression models controlling for seasonality. Associations between gender and data on health-seeking behaviour from the cross-sectional surveys were estimated using poisson regression models controlling for seasonality. RESULTS: Overall, incidence of malaria diagnosed per 1000 person years was 735 among females and 449 among males (IRR = 1.72, 95% CI 1.68-1.77, p < 0.001), with larger differences among those 15-39 years (IRR = 2.46, 95% CI 2.34-2.58, p < 0.001) and over 39 years (IRR = 2.26, 95% CI 2.05-2.50, p < 0.001) compared to those under 15 years (IRR = 1.46, 95% CI 1.41-1.50, p < 0.001). Female gender was also associated with a higher incidence of visits where malaria was not suspected (IRR = 1.77, 95% CI 1.71-1.83, p < 0.001), with a similar pattern across age strata. These associations were consistent across the 12 individual health centres. From the cross-sectional surveys, females were more likely than males to report fever in the past 2 weeks and seek care at the local health centre (7.5% vs. 4.7%, p = 0.001) with these associations significant for those 15-39 years (RR = 2.49, 95% CI 1.17-5.31, p = 0.018) and over 39 years (RR = 2.56, 95% CI 1.00-6.54, p = 0.049). CONCLUSIONS: Females disproportionately contribute to the burden of malaria diagnosed at public health facilities in Uganda, especially once they reach childbearing age. Contributing factors included more frequent visits to these facilities independent of malaria and a higher reported risk of seeking care at these facilities for febrile illnesses.

Remote bednet use monitoring to describe patterns of use and exposure to female Anopheles mosquitoes in an Ugandan cohort.

Background: Long lasting insecticide-treated bednets (LLINs) are the most widely used tool for preventing malaria. There has been a plateau in progress in the highest burden African countries since 2015, leading to questions about the effectiveness of LLINs. In this study, remote LLIN use monitors were deployed in a cohort in Eastern Uganda to explore how LLIN use interacts with mosquito exposure. Methods: The SmartNet study included 20 households from May to October 2019. SmartNet devices recorded, every 15 min, whether an LLIN was unfurled or folded up. Unannounced visits were used to assess SmartNet accuracy. Risk factors associated with poor LLIN use were assessed using generalized linear equations. Female Anopheles exposure was estimated by combining hourly probabilities of exposure from human landing catches and measures of density from biweekly CDC light traps in participants rooms. Mosquito exposure averted by LLINs was quantified using SmartNet measurements and age-related differences were estimated using generalized linear equations, adjusting for relevant covariates and household clustering. Results: 96 individuals contributed 5,640 SmartNet observation nights. In 126 unannounced visits, SmartNet had an area under the curve of 0.869 in classifying whether the LLIN was up or down. The rate of non-use was 13.5% of nights (95% CI: 12.6-14.3%). Compared to children under 5, non-use was 1.8 times higher (95% CI: 1.6-2.1; p < 0.001) in children 5-15 years and 2.6 times higher (95% CI: 2.2-3.1; p < 0.001) in participants aged 15-<30years. There was no difference between children under 5 years and adults > 30 years. LLIN use averted 50.3% of female Anopheles mosquito exposure (95% CI: 40.0-60.0%), with decreasing point estimates of efficacy across age groups: from 61.7% (95% CI: 42.6-80.7%) in children under 5 years to 48.0% (95% CI: 29.1-66.8%) in adults over 30. Conclusions: Objective monitors are accurate and can feasibly be deployed to obtain data about LLIN use. LLINs provided protection from only 50% of female Anopheles mosquito exposure in this cohort and protection was dependent upon age. In assessing the role of LLINs in malaria prevention it is crucial to consider the dynamics between mosquito exposure and LLIN use behaviors.